Since all the POIs are created from different lists, multiple for loops
were used. With itertools.chain these lists can be looped over with only
one for loop thus removing doubled code.
The code creating the actual marker dict out of the entity and the
result of the filter function was almost the same for every set of
entities. Thus it is now a function.
Instead of doing the UUID->name resolution for all players in every
case, only do it when EntityId is accessed and the name hasn't been
retrieved this run already. This makes genPOI usable for people who
have many players on their servers but don't wish to use player POI
while still using other genPOI features.
To do this, a PlayerDict has been created, which contains a dirty
hack to see if the requested item is EntityId and whether it hasn't
been set already.
The validator will now warn if it detects that a crushed output
is fed into something that is not a crusher.
The is_crusher method of an optimizer shall return True if the
optimisation process is lossless, and does try to find optimal
encoding parameters as opposed to only removing unneeded channels
or reducing palettes.
Before someone says this is incorrect because it only ever uses
pngcrush: The old code always used pngcrush and nothing else
anyway. This is absolutely correct and the old behaviour.
I also added a check to make sure it's a list, as some people might
forget the whole list thing.
There were some problems when a level.dat contained a non-ascii name, or
when a level.dat lived in a directory with a non-ascii name.
Paths returned by os.listdir are encoded, so we need to decode them
before printing them. When calculating the max length of the enumerated
world names, were we for some reason calling str() before taking the
len(). The had the effect of converting unicode strings into
non-unicode strings, which is not the correct thing to do.
For example, don't chmod if the filesystem dosen't support chmod, and
don't rename over files if that's not supported (this functionality was
already in place).
Should fix#1061
Related to #1055 (we could add a mtime capability flag)
